An absorption operation is one of methods for separating a specific component from a gas. The absorption operation method can be generally classified into a method that involves dispersing an absorbing liquid in a gas and a method that involves dispersing a gas in an absorbing liquid. In the former method, absorption towers such as a packed tower and a spray tower are used, while in the latter method, absorption towers such as a plate tower and a bubble tower are used. It is noted that such absorption towers are also known techniques disclosed in patent publication (e.g., see Patent Documents 1 and 2).
However, absorption devices such as absorption towers described above have a poor contact efficiency between an absorbing liquid and a gas. Hence, an absorption rate was low and it was difficult to increase an absorption amount per unit volume of an absorbing liquid.